Field of the Invention
The present invention relates to a fixing belt and a fixing device and an image forming apparatus using the same.
Description of the Related Art
In a fixing device adopted in an image forming apparatus such as a copying machine or a laser beam printer, a heated fixing belt is usually brought into contact with a recording medium carrying an unfixed toner image to fix the toner image onto the recording medium. Next, the recording medium onto which the toner image is fixed is separated from the fixing belt. The fixing belt is, for example, an endless belt in which abase layer, an elastic layer, and a release layer are laminated in this order.
In the elastic layer used in such a fixing belt, compatibility between high thermal conductivity and low hardness has been demanded in order to satisfactorily melt-fix the toner image onto the recording medium. As a technique that meets such a demand, for example, JP 2005-300591 A discloses a technique capable of controlling rubber elasticity while having high thermal conductivity by using a specific elastic layer including a thermally conductive filler (filler) and an additional reaction type silicone rubber cured product. More specifically, particle diameters having two peaks in the curves of the area ratio of the thermally conductive filler in the cross-section of the elastic layer in the thickness direction and the volume-based frequency distribution of the particle diameter of the thermally conductive filler and tan 5 in a dynamic viscoelasticity measurement at 180° C. are set within a predetermined range.
However, in the fixing belt using the conventional elastic layer, particularly, the elastic layer containing the filler as in JP 2005-300591 A, since the releasability between the fixing belt and the recording medium (for example, a sheet or the like) having the toner image melt-fixed thereon is not sufficient, there still remains a problem that defects caused by peeling occur in the obtained toner image.